MHT CET Medical202623 April 2026Morning ShiftBiologyMineral NutritionActual
How many electrons and ATP are required for the biological fixation of a molecule of nitrogen to form ammonia?
Options
- A4 and 8 respectively
- B2 and 4 respectively
- C8 and 16 respectively
- D16 and 32 respectively
Correct answer
C. 8 and 16 respectively
Step-by-step solution
The biological nitrogen fixation is catalyzed by the enzyme nitrogenase. The overall reaction for the reduction of one molecule of nitrogen ( N₂ ) to two molecules of ammonia ( NH₃ ) is given by: N₂ + 8e^- + 8H^+ + 16ATP 2NH₃ + H₂ + 16ADP + 16P_i From the balanced equation, the fixation of one molecule of nitrogen requires 8 electrons and 16 ATP molecules. Answer: 8 and 16 respectively